1. Field of the Invention
This invention relates, generally, to medical devices. More particularly, it relates to a miniature blood analyzer.
2. Description of the Prior Art
In addition to monitoring the vital signs of a patient under anesthesia during surgery, a number of other parameters are monitored as well. For example, the respective amounts of sodium, potassium, carbon dioxide, hematocrit-hemoglobin, and oxygen in a patient's blood are also monitored because such amounts must remain within certain critical limits.
The conventional way of monitoring the sodium, potassium, etc. content of a patient's blood is to take a blood sample from the patient, send it to the hospital's lab, and await the results of the analysis. Typically, the time delay between the taking of the blood sample and the delivery of the results to the surgical team is about forty five minutes in most hospitals. This is an unacceptably long time, however, because unacceptable levels of hematocrit-hemoglobin, sodium, etc., may be life threatening and the patient may not be strong enough to survive until the lab results are delivered. If a patient does survive the long wait, the needed action can be taken to reduce the arterial carbon dioxide content, for example, by changing the settings on a ventilator, etc., but another long wait must be endured before the next round of lab results are recived to indicate whether or not the patient is responding to the remedy. For a complex operation that requires many hours to complete, the number and spacing of lab reports is sometimes simply too few and far apart to be of significant value.
Information concerning the patient's condition is particularly critical when a patient is hemorraghing or in any other situation where transfusion of large amounts of blood is occuring. Physicians attending such highly unstable patients cannot long await lab results.
What is needed, then, is an improved means for analyzing a patient's blood. The improved means should substantially eliminate the forty five minute or more wait between the taking of a blood sample and the lab results. The improved means should be able to perform all of the tests typically performed by a lab, and it should be able to promptly inform the operating team of the lab results.
However, in view of the prior art as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how the needed means could be provided.